Pheochromocytoma in children and adolescents based on Polish Pheochromocytoma Registry

Pheochromocytomas and paragangliomas occur as sporadic tumors or in a familial context. It has been shown that approximately 25% of patients with pheochromocytoma and paraganglioma carry germline mutations in one of 4 susceptibility genes. Peripheral blood from unrelated, registry patients with pheochromocytoma was tested for mutations of RET, VHL, SDHD, and SDHB. Clinical data at first presentation and follow-up were evaluated. Among 136 patients (93 female and 43 male, 68,4% and 31,6% respectively; mean age, 45±14 years) who presented with pheochromocytoma, 34 (24,8%) were found to have mutations. Younger age, multifocal tumors, and extra-adrenal tumors were significantly associated with the presence of a mutation. There were 16 patients with pheochromocytoma under 20 years of age (9 female and 7 male, mean age 15,9±4,6 years, age range 5-20 years). Among them, we identified 15 patients with germ-line mutations (94 percent); 1 had M918T mutation of RET proto-oncogene resulting in MEN 2B syndrome, 6 had mutations of VHL gene, 5 mutations of SDHD gene, and 3 mutations of SDHB gene. Only two patients had positive family history at presentation. One fourth of patients with pheochromocytoma are carriers of mutations. Incidence of hereditary syndromes in patients under 20 years is 94%. Paraganglioma – pheochromocytoma syndrome resulting from SDHD or SDHB gene mutations (PGL1 and PGL4 syndrome, respectively) seems to be most common hereditary syndrome in Polish population of patients with pheochromocytoma under 20 years of age. Second major hereditary syndrome in this group was von Hippel-Lindau disease.